The invention relates to a circuit for controlling a thyratron in a conventional laser pulse discharge circuit, consisting of a high voltage supply, the output terminals of which are connected to a series connection of a primary coil, a diode and the thyratron, and a series connection of a condenser and the laser tube are connected parallel with the thyratron, and a secondary coil is connected parallel with the laser tube.
Such laser pulse discharge circuits have the disadvantage that the thyratron sometimes is latched up in its conductive condition, whereby the high voltage supply is shortcircuited. In order to avoid this problem various circuits have been developed such as, e.g. disclosed in WO 87/01882, which ensure that such a latch-up is prevented. However, such a circuit has various disadvantages as compared to the basic circuit described above. The circuit disclosed in WO 87/01882 increases the losses in the discharge circuit and the added components of the high voltage part entail a higher price, and an increased probability of malfunctions.